With a title like this you are probably wondering who cares?

Here is a simple explanation.
The hyper-focal distance is the near part of the depth of field (area of acceptable sharp focus) while your lens is focused at infinity. This means turning the focus ring on you cameras past 30 or 50 feet or whatever is the last mark on the focus ring of your particular camera.

Please note that depth of field does not drop of like the side of a cliff but rather tapers off.

With your lens stopped down to say an aperture of 11 or 16, as you look through the viewfinder you will get an idea of the area that is in focus.

Most Professional camera people have a chart with them that tells them that with a given aperture and a given distance from the subject and a given lens, (either a wide angle or telephoto) what the length of the depth of field is.

By pre-measuring the focus points as an actor moves around the set, the first A.C (assistant camera) person can keep the actor in focus.

Here is something you can use in your shooting.
For example lets say you set your zoom lens at the 50 millimeter setting on your video camera. I will assume that it has a target size similar to a 16mm film camera

Using an aperture of 5.6 with the camera lens focused at infinity. Let’s say the depth of field will be 40 feet 6 inches to infinity (now this is just for reference and I am not using actual values here)

The near part of this depth of field is called the “hyper-focal distance”. This is the 40 feet 6 inches mark. Now if you want to increase the depth of field all you need to do is change the focus from infinity to 40 feet 6 inches, (that’s right, reset the focus for this
point) and your depth of field will Increase by half as much again.

In other words the depth of field will now be 20 feet 3 inches to infinity. Trust me it works.